package net.minecraft.world.level.levelgen;

import net.minecraft.core.BlockPos;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.util.RandomSource;
import net.minecraft.world.attribute.EnvironmentAttributes;
import net.minecraft.world.entity.EntitySpawnReason;
import net.minecraft.world.entity.EntityTypes;
import net.minecraft.world.entity.monster.PatrollingMonster;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.level.CustomSpawner;
import net.minecraft.world.level.NaturalSpawner;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.gamerules.GameRules;

public class PatrolSpawner implements CustomSpawner {
	private int nextTick;

	@Override
	public void tick(final ServerLevel level, final boolean spawnEnemies) {
		if (spawnEnemies) {
			if (level.getGameRules().get(GameRules.SPAWN_PATROLS)) {
				RandomSource random = level.getRandom();
				this.nextTick--;
				if (this.nextTick <= 0) {
					this.nextTick = this.nextTick + 12000 + random.nextInt(1200);
					if (level.isBrightOutside()) {
						if (random.nextInt(5) == 0) {
							int playerCount = level.players().size();
							if (playerCount >= 1) {
								Player player = (Player)level.players().get(random.nextInt(playerCount));
								if (!player.isSpectator()) {
									if (!level.isCloseToVillage(player.blockPosition(), 2)) {
										int x = (24 + random.nextInt(24)) * (random.nextBoolean() ? -1 : 1);
										int z = (24 + random.nextInt(24)) * (random.nextBoolean() ? -1 : 1);
										BlockPos.MutableBlockPos spawnPos = player.blockPosition().mutable().move(x, 0, z);
										int delta = 10;
										if (level.hasChunksAt(spawnPos.getX() - 10, spawnPos.getZ() - 10, spawnPos.getX() + 10, spawnPos.getZ() + 10)) {
											if (level.environmentAttributes().getValue(EnvironmentAttributes.CAN_PILLAGER_PATROL_SPAWN, spawnPos)) {
												int groupSize = (int)Math.ceil(level.getCurrentDifficultyAt(spawnPos).getEffectiveDifficulty()) + 1;

												for (int i = 0; i < groupSize; i++) {
													spawnPos.setY(level.getHeightmapPos(Heightmap.Types.MOTION_BLOCKING_NO_LEAVES, spawnPos).getY());
													if (i == 0) {
														if (!this.spawnPatrolMember(level, spawnPos, random, true)) {
															break;
														}
													} else {
														this.spawnPatrolMember(level, spawnPos, random, false);
													}

													spawnPos.setX(spawnPos.getX() + random.nextInt(5) - random.nextInt(5));
													spawnPos.setZ(spawnPos.getZ() + random.nextInt(5) - random.nextInt(5));
												}
											}
										}
									}
								}
							}
						}
					}
				}
			}
		}
	}

	private boolean spawnPatrolMember(final ServerLevel level, final BlockPos pos, final RandomSource random, final boolean isLeader) {
		BlockState state = level.getBlockState(pos);
		if (!NaturalSpawner.isValidEmptySpawnBlock(level, pos, state, state.getFluidState(), EntityTypes.PILLAGER)) {
			return false;
		} else if (!PatrollingMonster.checkPatrollingMonsterSpawnRules(EntityTypes.PILLAGER, level, EntitySpawnReason.PATROL, pos, random)) {
			return false;
		} else {
			PatrollingMonster mob = EntityTypes.PILLAGER.create(level, EntitySpawnReason.PATROL);
			if (mob != null) {
				if (isLeader) {
					mob.setPatrolLeader(true);
					mob.findPatrolTarget();
				}

				mob.setPos(pos.getX(), pos.getY(), pos.getZ());
				mob.finalizeSpawn(level, level.getCurrentDifficultyAt(pos), EntitySpawnReason.PATROL, null);
				level.addFreshEntityWithPassengers(mob);
				return true;
			} else {
				return false;
			}
		}
	}
}